Add remote-launch endpoint

backend/index.ts

@@ -9,6 +9,7 @@ import config          from "./config"
 import fhirServer      from "./routes/fhir"
 import authServer      from "./routes/auth"
 import launcher        from "./routes/launcher"
+import launcherRemote  from "./routes/launcherRemote"
 import pkg             from "../package.json"
 import { globalErrorHandler, ipBlackList } from "./middlewares"
 
@@ -56,6 +57,7 @@ app.use([
 
 // The launcher endpoint
 app.get("/launcher", launcher);
+app.get("/remote-launch", launcherRemote);
 
 // Host public keys for backend services JWKS auth
 app.get("/keys", async (_, res) => {

backend/routes/launcherRemote.ts

@@ -0,0 +1,87 @@
+import { Request, Response }       from "express"
+import { bool, getRequestBaseURL } from "../lib"
+import LaunchOptions               from "../../src/isomorphic/LaunchOptions"
+
+
+export default (req: Request, res: Response) => {
+
+    let {
+        patient,   // patient ID if needed
+        provider,  // provider ID if needed
+        encounter, // encounter ID if needed
+        sim_ehr,   // bool - render in iframe if true
+    } = req.query;
+
+    // -------------------------------------------------------------------------
+    // External FHIR Server
+    // Must be provided as fhir_server parameter
+    // Must be valid URL
+    // Query parameters are ignored (removed)
+    // -------------------------------------------------------------------------
+    if (!String(req.query.fhir_server || "").trim()) {
+        return res.status(400).send("A fhir_server parameter is required");
+    }
+
+    try {
+        var fhir_server = new URL(String(req.query.fhir_server || "").trim());
+        fhir_server.search = "";
+    } catch (ex) {
+        return res.status(400).send("Invalid fhir_server url: " + ex);
+    }
+
+    // -------------------------------------------------------------------------
+    // App's launch url
+    // Must be provided as launch_uri parameter
+    // Must be valid URL
+    // Query parameters are ignored (removed)
+    // -------------------------------------------------------------------------
+    if (!String(req.query.launch_uri || "").trim()) {
+        return res.status(400).send("A launch_uri parameter is required");
+    }
+
+    try {
+        var launch_uri = new URL(String(req.query.launch_uri || "").trim());
+        launch_uri.search = ""
+    } catch (ex) {
+        return res.status(400).send("Invalid launch_uri url: " + ex);
+    }
+
+    // -------------------------------------------------------------------------
+    // FHIR version of the fhir_server server
+    // Must be provided as fhir_ver parameter
+    // Must be one of 2, 3, 4
+    // -------------------------------------------------------------------------
+    const ver = parseInt(req.query.fhir_ver + "", 10);
+    if (ver !== 2 && ver !== 3 && ver !== 4) {
+        return res.status(400).send(
+            "Invalid or missing fhir_ver parameter. It must be '2', '3' or '4'."
+        );
+    }
+
+    // iss ---------------------------------------------------------------------
+    const sim = new LaunchOptions({
+        launch_type: "provider-ehr",
+        fhir_server: fhir_server.href
+    })
+
+    const launchOptions = new LaunchOptions({
+        fhir_server: fhir_server.href,
+        launch_type: "provider-ehr",
+        sim_ehr    : bool(sim_ehr),
+        patient    : String(patient || ""),
+        provider   : String(provider || ""),
+        encounter  : String(encounter || "") || "NONE",
+        pkce       : "auto",
+        client_type: "public",
+    })
+
+    const iss = new URL("/v/r" + ver + "/fhir" + sim + "/fhir", getRequestBaseURL(req))
+
+    // Make sure we use the correct iss protocol, depending on the launch_uri
+    iss.protocol = launch_uri.protocol;
+
+    launch_uri.searchParams.set("iss", iss.href)
+    launch_uri.searchParams.set("launch", launchOptions.toString())
+
+    res.redirect(launch_uri.href);
+};